Assembly method for electrical devices



April 8, 1969 M. PAGANELLI 3,437,417

ASSEMBLY METHOD FOR ELECTRICAL DEVJCES Filed D60. 27, 1966 7 13 9 A a 6 6 I 1 I W H 11 5 I I j 74 I 1 72, 0

INVENTOR [hr/o BY flr, W J; a

ATTORNEY United States Patent 3,437,417 ASSEMBLY METHOD FOR ELECTRICAL DEVICES Mario Paganelli, Varese, Italy, assignor to Bassani, S.p.A., Milan, Italy Filed Dec. 27, 1966, Ser. No. 604,818

Claims priority, application Italy, Dec. 28, 1965,

. 28,842/ 65 Int. Cl. H01h 11/00; H01r 9/04, 13/50 U.S. Cl. 29-622 4 Claims ABSTRACT OF THE DISCLOSURE A switch housing has a terminal member secured in an apertured wall thereby by a deformed, initially dished washer secured in an annular groove in the member, on one side of the wall; and by a switch contact holding member swaged onto the member, on the other side of the wall.

This invention relates to a system for fixing the terminals to such electric devices, especially in private homes, as switches, push buttons, bells and the like, and more particularly to such devices, whose housing is made of pressed Bakelite or other similar materials.

With such materials the fixing of the terminals by means of screw connections is not suggestable because of possible carbonisation or ruptures which make any strong anchoring of the terminals impossible, thus becoming the last of dangerous use.

For such reasons, some countries prescribe standards prohibiting the use of terminals which are fixed to a device for being screwed into an insulating material, obtained by pressing.

The solutions heretofore proposed for this problem, were difficult and expensive.

The system of fixing terminals in accordance with this invention ensures a rigid fixation of the terminal to the electrically conducting parts and their locking to the electric devices in a simple and quick manner With improved stability of the terminal and the lowest expenditure.

In accordance with this invention, each terminal is strongly connected to the respective electrically conductive member, as for example a contact-holder, by means of a collar that is introduced into a hole in such member, which collar is then countersunk or upset, this collar being forced from inside into the corresponding hole of the housing containing the electric device, so that said member leans on the inner wall of said housing, after which the terminal is locked in place by a washer initially of truncated cone shape that is then pressed in order to engage itself by its inner border into an annular groove of the terminal, while its border bears on the external wall of the housing.

The object of this invention is shown as a not limitative example of realisation in the herewith enclosed drawing, relating to an electric switch.

Referring now to the drawing, 1 indicates the housing of an electric control device, made of insulating material; 2 is a tilting lever whose oscillations are controlled by through a spring 3, and whose movement elfeets the displacement of a double contact-holder 4 into two opposite positions in which two movable contacts Sand 6 are alternately contacted by fixed contacts 5 and 6, respectively.

The contact-holder 4 pivots over an electrically conductive bridge 7, while the fixed contacts 5 and 6' are supported by contact-holders 8 and 9, respectively.

To the contact-holders 8 and 9 and the electrically, conductive bridge 7 there are connected the terminals 10, 11

and 12, to which are attached the electric wires of the strong locking of said members upon the aforesaid upsetting of these collars.

The terminals are then inserted into respective holes 10', 11 and 12' bored at the bottom wall of the electric control device, said insertion being effected from the inside of said device.

For fixing each one terminal to the device, each terminal is provided with a washer 15, which is inserted along the respective portion of the terminal which extends outwardly from the device so as to bear against the external wall of said device.

Washer 15 is initially a dished annulus, that is the Washer is of truncated cone shape as illustrated in the drawing in phantom line, and its central opening is such as to embrace the cross section of the terminal. Said washer is then pressed axially together to receive a flattened shape, so that its central opening is restricted thus strongly embracing an annular groove 14 provided for in the terminal, While its external border leans against the external wall of said electric device, thus being locked in place, and locking the terminal as well.

As it results from the above, the fixing operation of the terminals takes place in a very quick manner, while in the same time a strong connection is ensured between the terminals and the electrically conductive members.

Of course, the invention can be realised in other manners, different from that one hereinabove described and illustrated in the attached drawing, as specified in the attached claims.

What I claim is:

1. An assembly method of the character described, wherein an elongated member provided with two end portions and an outer circumferential groove intermediate said end portions extends through an aperture in a wall means so that one end portion is located at one side of said wall means and the groove and the other end portion are located outwardly adjacent to the other of said sides, comprising extending a part of said one end portion from a first to a second side of an electrically conductive element through a hole provided in the latter and which element partly overlies and abuts against said one side maintaining said member against movement towards said other side; upsetting such part at said second side so as to prevent withdrawal from said hole; placing around said other end portion a dished annulus surrounding such other end portion with small clearance; and deforming the annulus from its dished into a plane condition whereby the inner circumferential edge portion of the annulus enters into said groove while the remainder of the annulus abuts against said other side of said wall means and prevents movement of said member in direction towards said one side.

2. A method as defined in claim 1, wherein said wall means constitutes a part of a housing and said one side faces the interior of such housing, and wherein said member is initially introduced through said aperture from the direction of said one side.

3. An assembly method as defined in claim 1, wherein steps 3 and 4 are carried out prior to steps 1 and 2.

4. An assembly method as defined in claim 1, said part being tubular and having an open end located at said second side of said element when said part is extended through said hole; and wherein the step of upsetting said 4 part comprises radially outwardly deforming the material 2,746,023 5/ 1956 Tyzack 339126 of said part at said open end so that the thus deformed 3,218,606 11/1965 Schultz 339-131 FOREIGN PATENTS material overlies a marginal zone of said second side sur- 7 i 1,381,189 10/1964 France.

rounding said hole.

References Cited 0 179,063 5/ 1922 Great Britain. UNITED STATES PATENTS 179,547 4/ 1923 Great Britain.

2,513,080 6/1950 Burtt 339195 X RICHARD E, MONROE, Primary Examiner. 3,051,803 8/1962 Brown 200168 X U S C1 XR 3,336,570 8/1967 Tuchel 339220 10 2,461,487 2/1949 Wagstalf 339129 339220, 214; 29512, 520, 630

2,737,635 3/1956 Lane 339126 

